I have a project on ultrasonic transducer, the bug here is that I have to choose one application of ultrasonic transducer and do that project. The project should include measurement of the time of flight of the ultrasound waves to determine whatever is it that we want the transducer to do.

Help on choosing the application which is simple that uses the ultrasonic transducer...

Anything is feasible, given enough time and money. What is your criteria for "better"?

I've never worked with ultrasonic devices, but it seems you need a transmitter and a receiver. The receiver (something like a microphone) will have to be amplified, and then you will need to detect thresholds to determine the distance, or reflected distance.

I'm guessing this shouldn't be too difficult as you will be using frequencies well below the megahertz band. I suggest you do some searching on the Internet for ultrasonic ideas.